houseplan-card/docs/ARCHITECTURE.md

House Plan architecture

Updated: 2026-07-04 (v1.2.2). The repository = a HACS integration (category Integration) that contains both the backend (custom_components/houseplan) and the Lovelace card (src/ → dist/).

Layout

houseplan-card/
├─ src/                          # card sources (TypeScript + Lit 3)
│  ├─ houseplan-card.ts          # the card: rendering, states, drag, tooltip, sticky header
│  ├─ editor.ts                  # GUI config editor (ha-form + selectors)
│  ├─ rules.ts                   # icon rules (iconFor), filtering, groups, domain priority
│  └─ data/
│     ├─ house.ts                # geometry: ROOMS (rooms→area), FLOOR_VB (viewBox), names
│     └─ backgrounds.ts          # VECTOR plans (SVG base64) + FLOOR_BG_RECT (positioning)
├─ dist/houseplan-card.js        # build (rollup+terser), ~290 KB, plans embedded
├─ custom_components/houseplan/  # the HA integration
│  ├─ __init__.py                # setup: Store, WS commands, JS serving (add_extra_js_url)
│  ├─ websocket_api.py           # houseplan/layout/get|set|update
│  ├─ config_flow.py             # single entry; admin_only option (editing restricted to admins)
│  ├─ const.py                   # DOMAIN, STORAGE_KEY, VERSION, FRONTEND_URL
│  └─ frontend/houseplan-card.js # copy of dist, served as /houseplan_files/houseplan-card.js
├─ hacs.json                     # HACS manifest
└─ docs/                         # this documentation

Key decisions

1. One repository — integration + card. The integration serves the JS (async_register_static_paths) and registers it as a Lovelace resource (module) — the frontend waits for resources before rendering, so the card also works on a cold start of the mobile app (unlike add_extra_js_url, which remains a fallback for YAML mode). The user does not need to add the resource manually.
2. Icon layout lives on the server. helpers.storage.Store(1, "houseplan.layout") → .storage/houseplan.layout. The card reads/writes via hass.callWS (houseplan/layout/get|set|update). Fallback — localStorage (when the integration is absent).
3. No token. Everything comes from the frontend hass object: hass.states (reactive), hass.devices/entities/areas (registries). No direct WS connections.
4. Reactivity. Every state change in HA leads to set hass → re-render. Temperatures/LQI/on-off are live by definition (verified by substituting state).

Coordinate system

• Base space: 1489×1053 ("pixels" of the old PNG render, 1 unit = 1 px). All rooms, icon positions and floor viewBoxes live in it. DO NOT change without a layout migration.
• Vector plans are inserted as <image href=svg> into the FLOOR_BG_RECT rectangle:
  • f1: scale 0.647, offset (490, 27) → rect [490, 27, 774.2, 949.3]
  • f2: scale 0.896, offset (351, 21) → rect [351, 21, 1048.4, 961.4]
  • computed via raster correlation (cv2.matchTemplate on binarized darkness maps) of the SVG render against the reference PNG; accuracy ~1 px. The scripts are reproducible (docs/DEVELOPMENT.md).
• Rooms (ROOMS) are snapped to the inner faces of walls (semi-automatic: search for the nearest "dark line" along the profile + manual fine-tuning against overlay renders).

Card data model (runtime)

DevItem: id (device_id), name, model, area, floor, icon, entities[], primary (the entity used for more-info by domain priority), temp, members[] (light group), link/linkPrimary (Z2M group).

Built from the registries (_buildDevices), rules carried over 1-to-1 from the prototype:

• only devices with an area from the room list are shown;
• hidden: entry_type=service, integrations from EXCLUDED_DOMAINS, model=Group, scenes, bridges, myheat sub-devices, duplicates by "name|area";
• a device with a lock.* entity always gets mdi:lock (TTLock locks in the registry are named "Dom"/"Terrasa"/"Kladovka" [House/Terrace/Storeroom] — unrecognizable by name);
• lamps (mdi:lightbulb) with ≥2 in a room collapse into a group mdi:lightbulb-group (click → menu: the whole group + individual lamps).

Live data

• Temperature: an entity with device_class=temperature / °C / _temperature$ → label on the right.
• LQI (zigbee): the average over *_linkquality entities → label under the icon; color via lqiColor(): ≤40 red → ≥180 green (hsl gradient). The room average is shown in the room tooltip.
• Icon state classes: on (yellow), open (orange: cover/valve/lock/binary_sensor of problem classes), unavail (transparency).

Sizes

icon_size in the config = % of the visible plan area width (default 2.5). Implementation: .stage { container-type: inline-size } + sizes in cqw. Legacy px values (>8) are ignored.

Sticky header

.head { position: sticky; top: var(--header-height, 56px) }; it is MANDATORY that ha-card { overflow: visible } — overflow: hidden breaks sticky.

Device markers (v1.6.0+)

Per-marker appearance (v1.22.0): display: badge|ripple|icon_ripple (+ripple_color, ripple_size) draws presence-style pulsing rings gated by the pure isActiveState — deliberately independent of the card-wide live_states toggle, with unavailable counting as idle. size (icon multiplier via the --dev-size CSS var — value badges scale along) and angle rotate/scale a single icon. Room drawing shows a live ruler (segmentCm + formatLength, metres or feet+inches by hass.config.unit_system); the scale is per-space cell_cm (default 5 cm per grid cell).

config.markers[]: {id, binding:'device:<id>'|'entity:<eid>'|'virtual', space?, area?, hidden?, name?, icon?, model?, link?, description?, pdfs:[{name,url}]}. A hybrid: auto-discovered HA devices appear on their own; a marker with binding=device:<id> overrides them (metadata/rebinding/hiding), entity:<eid> — for groups/helpers, virtual — a manual icon without HA. The marker id = device_id / lg_<eid> / v_<rand> (preserves the position in the layout). The binding picker excludes already-placed references and duplicates by name|area. Manual files: transactional HTTP upload into <config>/houseplan/files/<id>/ (staging up_* folders promoted on save), served via signed /api/houseplan/content/files/… urls.

Server-side configuration (current shape, v1.51+)

.storage/houseplan.config (Store):

{ "spaces": [{ "id","title","plan_url","plan_aspect","view_box":[4],
               "rooms":[{"id","name","area","poly|x/y/w/h","open_to","settings"}],
               "openings":[…], "decor":[…], "settings":{…} }],
  "markers": [{ "id","binding":"device:<id>|entity:<eid>|virtual","hidden",
                "name","icon","display","controls","is_light","tap_action",
                "room_id","pdfs",… }],
  "settings": { "exclude_integrations":[], "group_lights":true,
                "filter_seeded":true, "fill_colors":{…}, "icon_rules":[…],
                "known_devices":[…], "new_device_ids":[…] } }

All coordinates are normalized (0..1 of the canvas); the canvas is always square (v1.48.0), render space NORM_W × NORM_W (1000×1000). A space has no proportions of its own — plan_aspect is the IMAGE's ratio, used to letterbox it centred on the square. The schema bounds geometry to ±4 with strictly positive sizes (HP-1501/1502). device_overrides/virtual_devices are long gone — markers carry everything, marker.hidden is the explicit "hide from plan" flag seeded once by the old filter (docs/FILTERING.md). Layout v2: {device_id | rl_<roomId>: {"s": space, "x", "y"}} (normalized, bounded ±4). Plan files: <config>/houseplan/plans/<space>.<token>.<ext> (copy-on-write, never overwritten), served via signed /api/houseplan/content/plans/_/<name> urls; growth is bounded by store quotas, nothing is ever deleted for being old (docs/SCOPE.md).

Room geometry rules (v1.19–v1.21)

A line is never an entity of its own: walls are derived from room outlines (roomEdges, deduped by segKey), so an abandoned outline leaves nothing behind and deleting a room keeps the walls its neighbours still contribute. Rooms may not overlap (pointStrictlyInside + roomsOverlap; being ON a shared wall is legal — real neighbouring walls overlap collinearly rather than match exactly). Merge/Split use boolean geometry from polyclip-ts (chosen over polygon-clipping, whose ESM build exports only a default while its types declare named exports — breaking either tsc or the runtime): merge accepts a pair only when the union collapses into one hole-free outline; split cuts wall-to-wall with a chord, the bigger part keeps the room identity (name/area/devices).

Markup editor (v1.4.0+)

State inside the card: _markup (mode), _tool (draw/delroom), _path (the current outline, vertices on the GRID_N=240 grid). Clicks on the stage → _svgPoint→_snap. The outline is closed = a click on the first vertex → area select (hass.areas) + name → room {poly}. Polygon rooms and rectangles are rendered uniformly (hit-test: point-in-polygon / rect).

A line is never an entity of its own (v1.19.0). Nothing is persisted while you draw: an outline you never close leaves no trace. Walls are derived from the room outlines by roomEdges(rooms) (logic.ts) and deduped by segKey, so a wall shared by two rooms is emitted once — deleting a room therefore keeps the borders its neighbours still contribute and drops the rest, with no bookkeeping. The legacy space.segments array is stripped on every save (validation still tolerates it on read; see CHANGELOG v1.19.0).

While drawing, the length of the current segment follows the cursor (_fmtLen → segmentCm/ formatLength): metres, or feet+inches when hass.config.unit_system is imperial. The scale is per-space cell_cm — cm represented by one grid cell (default 5, so 240 cells ≈ 12 m).

Doors & windows (v1.23.0+)

space.openings[] — plan geometry, not markers: an opening needs an angle, a length and a wall, while markers are free points whose positions live in the layout store. Model: {id, type: door|window, x, y, angle, length, contact?, lock?, invert?, flip_h?, flip_v?} (normalized coords; length normalized by plan width). Placement snaps onto the nearest derived wall via snapToWall (logic.ts) — the angle is normalized to [-90, 90) because two rooms share a wall with opposite edge directions, and without that a drag across segment boundaries flips the hinge. The opening then keeps absolute coordinates, so editing, merging or deleting rooms never breaks it.

Rendering (after easy-floorplan, MIT): SVG symbol at the origin (jambs + hinged leaf + a quarter-circle arc revealed via stroke-dashoffset), translated/rotated onto the wall; windows are two casement leaves. openingAmount (pure) maps the contact state to 0..1: no sensor → door drawn open / window closed (static-plan convention); unavailable/unknown freeze that default. The lock renders as an HTML padlock badge (.oplock) in the device layer; a lock is never toggled from the plan (TOGGLE_FORBIDDEN_DOMAINS rule). View-mode UX: hover outline, drag along walls (continuous re-snap, saved on release), click → status card (250 ms timer), double click → properties dialog. In markup mode the "Opening" tool handles clicks instead.

Integration WS API

Command	Parameters	Response
houseplan/layout/get	—	{layout: {device_id: {x,y}}, rev}
houseplan/layout/set	layout, expected_rev?	{ok, rev} / err conflict; event houseplan_layout_updated
houseplan/layout/update	device_id, pos	{ok, rev}; event houseplan_layout_updated
houseplan/config/get	—	{config, rev}
houseplan/config/set	config, expected_rev?	{ok, rev} / err conflict; event houseplan_config_updated
houseplan/plan/set	space_id, ext (svg/png/jpg/webp), data (b64, ≤8 MB)	{ok, url} — writes <space>.<token>.<ext>, deletes nothing
houseplan/plans/list	—	{plans: [{name, url, size, modified, used_by}], total} (newest 60)
houseplan/plans/delete	name	{ok, removed} / err in_use
houseplan/layout/delete	device_id	{ok, rev}; event houseplan_layout_updated
houseplan/geometry/repair	space_id, aspect, dry_run?, undo?	preview / {ok, rev, moved} / {restored}; errs nothing_to_repair, no_backup
houseplan/files/migrate	from_id, to_id	{mapping} — COPY, never move
houseplan/files/cleanup	marker_id, keep?	replacement-only collection
houseplan/content/sign	paths[]	{urls} — authSig for <image>/<a> fetches

Manual attachments upload over HTTP (streaming, transactional staging), not WS — the old houseplan/file/set was removed in v1.10.0.

If the v1.48 migration crashed halfway (HP-1500-01): the config write landed, the layout write did not, and both triggers are gone — markers of that space sit in the old coordinates and nothing in the data can prove it. The geom_pending intent (v1.50.0) prevents this for any future migration, but cannot help an install that was already stranded. There is no safe automatic answer — re-transforming a layout that is actually correct would corrupt it — so the fix is explicit: houseplan/geometry/repair {space_id, aspect} re-applies the transform to that one space's positions. dry_run: true previews, the previous positions ride the same store write as a one-deep backup, and undo: true restores them. Admin-gated like every other write.

The canvas is square, the image is not (v1.48.0). A space used to carry an aspect, and coordinates were normalised against it — x by the width, y by the height. That made every geometric question depend on a per-space number for no benefit. Now the render space is NORM_W × NORM_W and a plan image is fitted inside it by its own ratio (fitInSquare, shared by both renderers), which is stored as plan_aspect so the layout does not jump before the file loads. Upgrading runs geometry_migration.migrate_config once: it pads the old box out to a square and re-expresses every coordinate against it — a uniform scale plus an offset in render units, so angles and proportions are exact — and scales cell_cm for tall plans, since the grid pitch is a fraction of the width.

User content is served inert (HP-1454-01). An uploaded SVG is the only thing here that a browser will happily treat as a document rather than an image, and it would be a document of Home Assistant's own origin. Inside the card that never matters — <image> does not run scripts — but the url is reachable directly, and uploading needs only write access, which by default every user has. HouseplanContentView therefore sends a sandbox CSP with SVG and only with SVG: a CSP on a PDF response can break the browser's built-in viewer, and a raster image has no execution model to disable.

Attachments follow the same commit-scoped lifecycle as plans (HP-1454-02). An upload takes a free name and never overwrites, because the bytes under an existing name may be referenced by the stored configuration and an upload is not part of that transaction. reserve_filename claims the name as it picks it (O_CREAT | O_EXCL) — asking exists() and returning a string let two uploads agree on one name and quietly overwrite each other. It also budgets the length so the result survives the sanitiser the content view applies to the request, since a name the view rewrites is a file written and never served. Streaming temporaries live in the files root under .upload-, are removed on every exit path of the request (including cancellation, which is a BaseException and slips past except Exception), and are swept at startup and daily. That scheduled pass also runs the two collectors with the stored configuration as both sides — nothing superseded, so every referenced file is kept and only aged unreferenced ones go. Without it, collection would only ever happen when somebody saves, and a file uploaded into a dialog that was then cancelled would wait for a write that may never come. A new icon has no id yet, so its files go to a per-dialog staging folder and move to the real id once the config write is accepted — the same copy → save → cleanup order as a rebind. config/set collects what its commit superseded — that much a commit knows for certain. Unreferenced is a far weaker signal, and the policy follows from one asymmetry: a few unnecessary megabytes can always be removed by hand; a file we should not have removed cannot be brought back. When the evidence is weak, keep the file. Owner's decision, 2026-07-28, after the one-hour rule applied to every unreferenced file destroyed two detached plans.

The classification is by owner, not by "is it referenced". A file leaving the configuration looks identical whether the plan was replaced, detached, or its space deleted — and only the first is a deletion the user asked for. Reading old_refs - new_refs and calling it "superseded" deleted a plan the moment it was detached, under documentation promising the opposite (HP-1465-01).

Case	What it means	Rule
Space in both, plan A → plan B	the user picked another image	removed immediately
Space in both, plan → none	detached; one click undoes it	kept
Space gone	deliberate, but the image was imported and may be nowhere else	kept
Space has a plan, plus another file of its own	an upload whose save was rejected	kept — ageing these out raced the retry that referenced them
Marker in both, attachment dropped from its list	a trash button, promising nothing	removed immediately
Marker gone	same call as a deleted space's plan	kept
Attachment in up_*	a dialog that was never saved; no device owns it	PLAN_ORPHAN_TTL_S (1 h)
Marker there, file it never listed	a rejected upload	kept, same reason

Nothing is deleted for being old, with one exception: a per-dialog staging folder (up_*), which by construction can only hold an upload from a dialog that was never saved. The disk therefore stays bounded by the user, not by a timer — houseplan/plans/list shows every stored plan with its size and which space uses it, and houseplan/plans/delete removes one on request, refusing while a space still references it. That listing is what makes "we never delete" livable: a detached plan is not lost, it is one click away in the space dialog.

Config writes are serialized (HP-1454-03). _writeConfig() chains onto a single promise: one config/set in flight, each carrying the revision the previous one returned. The debounce still spaces out when a write starts; what it cannot do — and used to be relied on for — is keep two writes from overlapping, which produced a self-inflicted conflict and lost the newer edit.

Plan uploads are copy-on-write, and collection belongs to the commit (reviews R2-1, R3-1). The file system is not part of the config's optimistic-locking transaction, so nothing referenced may be overwritten or deleted before the CAS succeeds: the upload writes a new versioned name and removes nothing. Deciding what may then go is not a client's call — a cleanup request cannot be ordered against another client's commit, and a delayed one deletes a plan that was just saved. So config/set collects itself, inside its write lock, from the pair of configurations that bracket the commit (plans.collect_plans): a file the commit REPLACED goes immediately, and nothing else goes at all — see the table above; only a per-dialog staging folder ages out. Growth is bounded at the door instead, by plans.check_quota on every upload (store size, file count, free disk), because a limit that deletes is how plans were lost twice. The . between id and token is load-bearing — a space id cannot contain one, so <space>.<token>.<ext> can never be confused with the files of a space whose name merely starts the same way.

An internal plan url must exist when it is stored (HP-1470-02). The picker can attach a plan and then delete it, and two clients can do the same in either order — the write lock orders the requests but says nothing about whether the file survived. config/set therefore checks every /api/houseplan/content/plans/ url against the disk before saving, and refuses with missing_plan. External and legacy urls are the user's own and are never second-guessed.

Signed content urls are batched, aged and deduplicated (reviews R2-2, R3-2, R4-2). ContentSigner in src/signing.ts is the single implementation, used by both cards; the duplicate inside houseplan-space-card signed correctly and never handed the result to its renderer, which is the failure mode a second copy invites. MAX_SIGN_PATHS (200) is a shared contract between logic.ts and const.py: the backend caps a request there and says nothing about the rest, so the card must chunk. Cached signatures carry the time they were issued — an aging one keeps rendering while its replacement is fetched, an expired one is dropped rather than served (it would 401 and raise a failed-login warning). The cache is pruned to the urls the live config references, so it cannot grow past the cap through history alone. Queued and in-flight are distinct states: a render happening while a request is out must not queue the same url again, a failure backs off rather than retrying on the next frame, and an in-flight entry expires after SIGN_INFLIGHT_MS so a promise that never settles cannot block retries forever.

Room climate is one pass per hass snapshot (review R2-3). areaClimateMap() classifies the whole registry once and returns Map<area, {temp, hum}>; the card memoizes it on hass identity, which Home Assistant replaces on every state change. Per-room lookups are O(1). areaClimate() survives as a single-area wrapper for tests — using it in a render reintroduces the O(rooms × entities) cost it was extracted from.

File uploads go over HTTP (not WS, which has a message-size limit): POST /api/houseplan/upload (multipart: marker_id + file), HomeAssistantView, requires_auth. Served from /houseplan_files/files/.

Second card: houseplan-space-card (read-only, v1.16.0)

The bundle registers two custom elements from one entry (src/houseplan-card.ts imports ./space-card):

• houseplan-card — the full interactive card.
• houseplan-space-card — a static, read-only schematic of ONE space for embedding.

Shared, framework-light modules keep the two views from diverging:

• src/space-geometry.ts — pure model/position math (spaceModels, roomBounds, roomCenter, defaultPositions, markerPos, labelPos; no Lit import) — unit-tested, mirrors the full card's private geometry.
• src/space-render.ts — renderSpaceStatic() draws the plan + configured room borders/names + device markers (via buildDevices, same filtering) with NO handlers, NO live states, NO status/temperature fills. Uses the same CSS classes as the full card (the space-card imports cardStyles) for visual parity.
• src/config-store.ts — module-level {config, rev, layout} cache shared by all embedded cards (dedupes houseplan/config/get), seeded synchronously from the full card's localStorage snapshot (houseplan_card_cfg_v1) and invalidated on houseplan_config_updated.

Static contract: the schematic layer (.hp-static-stage) is pointer-events:none; the footer button lives outside it and stays clickable.

Deep-link contract: the footer button calls navigate(button_target + "#space=<id>") (default target /plan-doma). The full card reads #space=<id> on load (a valid id wins over default_floor) and on hashchange, without blocking manual space switching; an invalid/absent hash falls back to the default.

Additions v1.28–v1.41 (2026-07-24)

• Decor layer (space.decor[], v1.33): purely visual shapes (line/rect/ellipse/text, normalized coords, per-shape style) drawn in the SVG right above the background image and BELOW rooms; pointer-events only inside the Background editor. Validated by DECOR_SCHEMA (vol.Any of the four kinds).
• Glow fill (v1.35+): fill_mode: 'glow' paints every room with fill_colors.glow_base and renders per-source radial gradients clipped by a per-light clipPath = zone polygons + doorway sectors, each contour a SEPARATE clipPath child (children union; subpaths of one nonzero path cancel on opposite windings — field bug v1.36.3). Radius: global settings.glow_radius_cm + per-marker glow_radius_cm.
• Open boundaries (v1.37): room.open_to: [roomId] symmetric links; light zones are connected components (openZoneOf); shared stretches computed by collinear-overlap math (sharedBoundary) and drawn as a TRUE dash — both room outlines and derived wall segments are trimmed (outlineWithout/cutSegments).
• Marker controls (v1.36): marker.controls[] (lights/switches only) toggled as one HA-group-semantics service call on the marker's EXPLICIT tap_action=toggle; icon state/tint mirrors the targets. primaryEntity picks in tiers so domain priority beats registry hidden (grouped lamps).
• Island rooms (v1.34): full nesting is legal (polyContainsPoly); parents render as evenodd paths with holes (islandsOf).
• Kiosk mode (v1.41): a card-config flag, not a mode — _setMode is hard-blocked, header hidden, swipe/carousel handled in the stage pointer pipeline (swipeTarget), per-screen multipliers in LS_KIOSK.
• Nav persistence (v1.38.2): LS_NAV stores {space, mode}; hash deep-link > saved > default_floor; stale-cache retry after the live load.

Settings tiers (owner's principle, 2026-07-26)

Four levels: global (config.settings) → space (space.settings) → room (room.settings) → device (marker.*). Duplicated options are deliberate: the more specific tier overrides the more general one; "unset" always means "inherit". Resolution lives in pure helpers (spaceDisplayOf, roomFillModeOf, sourceValue, resolveTapAction) — never inline in render. The UI will later be unified around this model; until then each tier keeps its own dialog (general settings gear / space gear / room-card gear / marker dialog).

Audit follow-ups (2026-07-27)

• Content is authenticated. /houseplan_files/… now serves ONLY the card bundle (a Lovelace resource must be public). Plans and marker files go through HouseplanContentView (/api/houseplan/content/<plans|files>/…, requires_auth). contentUrl() rewrites legacy stored URLs on read, so no storage migration is needed. Static paths cannot be unregistered — the old routes survive until the next HA restart.
• Optimistic UI, stated explicitly (audit L7). _serverCfg is mutated in place before a fallible save in ~22 places and there is no rollback: after a rejected save the UI shows the edit until the next reload. This is a deliberate optimistic-UI choice, not drift. Paths where it is unacceptable need their own rollback.
• Split invariant. splitRoomPath guarantees a partition: the two parts' areas sum to the original (within epsilon) or the cut is rejected.